The present invention relates to a closure for a wrap-around sleeve, particularly for a recoverable sleeve and particularly for use in the cable accessories field.
Sleeves may be used in many instances where elongate substrates such as cables or pipes or splices or joints therein are to be sealed, insulated or otherwise environmentally protected. In order to provide environmental protection, the sleeve may be provided with an adhesive or sealant, may be dimensionally-recoverable (particularly shrinkable, especially heat-shrinkable), may be provided with mechanical means to cause it to engage the substrate, or two or more of these features may be provided.
Where an end of the substrate is not accessible or where space is limited, installation of a tubular sleeve closed in cross-section may be impossible or difficult. For such situations, wrap-around sleeves have been developed. A wrap-around sleeve is simply an article generally of a plastics material such as a polyolefin, having means for securing it in a wrappedaround configuration. In particular such a sleeve may comprise a sheet of a flexible recoverable plastics material having an adhesive on a surface that will be inwardly facing when installed.
A recoverable wrap-around sleeve of particular use for enclosing joints in pipes or splices in telecommunications or power cables is disclosed in U.S. Pat. No. 3,455,336. The sleeve therein disclosed has an upstanding protrusion, known generally as a rail, running along each of two opposing edge regions. A channel, generally C-shaped in transverse cross-section, may be slid over the rails to hold them together and thus to hold the sleeve in its wrapped-around configuration. The rails may be undercut adjacent the surface of the sleeve such that the channel can be slid onto the rails longitudinally rather than pushed over transversely; the reason of course is so that the channel can grip the rails to prevent the rails pulling out of the channel due to the force of recovery of the sleeve or to other mechanical forces tending to separate the rails.
Such a channel is in general perfectly satisfactory, although difficulty can be experienced when the sleeve, and consequently also the channel, is very long, say at least 60 cms, especially at least 80 cms, particularly at least 100 cms. The difficulty arises partly because of the friction between a long sleeve and a long channel, and partly because of the space required which must accomodate the length of the sleeve and of the channel. The second problem may be reduced if the channel is flexible such that it can be longitudinally bent.